In order to reduce electric quantity consumption of a terminal device and increase standby time, the terminal device will use a DRX (discontinuous reception) mode to receive data or use a DTX (discontinuous transmission) mode to transmit data when the terminal device is in an idle state or in a state with no data being transmitted and received. Where, the DRX is a method for elongating service time of a battery in a radio communication system. Since the terminal device only needs to monitor the paging channel in the DRX group to which the terminal device belongs, rather than monitor the paging channel continuously, the electric quantity of the battery is saved.
Due to the diversified development of terminal devices, for example, taking a terminal device applied in M2M (machine to machine) technologies as an example, the terminal may be installed in an environment where it is impossible to be charged for long periods of time, thus, the requirement for saving power is particularly high. Although it is possible to save power by using the abovementioned conventional DRX mechanism, the terminal still needs to wake up in a relatively short period, which cannot meet the requirement for saving power of the terminal device.